Free Nightingales in November by Mike Dilger

fat reserves beforehand. However, they will not be flying with the fuel tank needle hovering just above empty, as deposits may well be needed for insurance should they hit any adverse weather conditions along the way. Also, reserves will be essential when crossing inhospitable areas, such as the Sahara Desert or Mediterranean Sea. Catching insect prey as they go means that the Swallows will need to travel mainly during the day, rather than at night, with migrating birds mostly seen anywhere up to 18 metres above the ground. While on the move, they seem to prefer flying into a headwind or crosswind, which makes it easier for the birds to hunt low down without fear of stalling in mid-air.
    On a good day they are believed to cover anywhere between 200 and 300km, and will try to find good roostingsites like reedbeds or dense grasslands each evening to lay up before starting out again early the following morning. Thought to travel in a north- to north-westerly direction as they leave South African airspace, late February should see our British Swallows moving through Namibia and Botswana and over the peculiar panhandle of the Namibian Caprivi Strip as they press on into Angola and Western Zambia.

    With the Congo Basin still ahead of our Swallows, most British Cuckoos will still be in the Congo towards the end of February, with the majority of satellite transmitter readings centred around the mighty Congo River. The time at which they too decide to leave their wintering grounds will be quickly approaching, but unlike the ‘feed on the wing’ technique of the Swallows, the Cuckoos will carry out their spring migration back to Britain in a series of long-distance hops, with clear breaks to rest and feed up in between. With their departure imminent, the Cuckoos will almost certainly be trying to eat well and rest as much as possible before their first leg, which will see them travel anywhere from 500km to 2,000km in a northwesterly direction away from the Congolian swamp forests.

    With the Cuckoos on the verge of leaving, most adult Puffins will be steadily working their way back to their natal colonies by late February. When airborne, the Puffin is thought to be able to cruise at around 58km per hour, and so could theoretically travel long distances quite rapidly. But with their short wings needing to beat at a frankly astonishing 400 beats a minute to keep the bird airborne, the energy demands this places upon them would require them havingto regularly pitch down on the sea to replenish their reserves before carrying on. As the waters around most British puffinries won’t see Puffins in any large numbers before at least the middle of March, this would suggest that arriving at their breeding grounds in good condition is distinctly more important than arriving back early.

    Returning too early to their north Russian breeding grounds would simply mean that the Bewick’s Swans would be unable to eat, because their breeding grounds on the maritime tundra would still be covered with snow, as well as the adjacent coastal waters probably still being frozen. Nevertheless, with the swans needing to make at least a couple of substantial refuelling stopovers before reaching the tundra, late February will see the majority of birds leave sites such as WWT Slimbridge as they conduct the first leg of their journey to the continent. The birds don’t all tend to leave in one flock, but numbers will fall away as the month progresses, with a few key nights seeing large numbers leave together.
    James Lees, one of the WWT wardens at Slimbridge, has been lucky enough to see a few large departures over the years, and says that a few days before the swans depart they become decidedly nervous at feeding time. They will also spend substantial parts of the day sleeping, no doubt to conserve energy for the flight to come. The majority of the swans will only leave when the conditions are right - favouring dark, clear nights with plenty of stars to aid in